1. Field of the Invention
The present general inventive concept relates to a method of compensating sensor data and evaluating an interlock of an interlock system, and more particularly, to a method of compensating sensor data and evaluating an interlock of an interlock system, in which the interlock is properly secured by accounting for a drift offset and/or a shift offset of the sensor data.
2. Description of the Related Art
In a semiconductor fabricating process, a process of fabricating each unit costs a great deal, and quality and productivity of a semiconductor are affected by a state of fabricating equipment. Therefore, problems with the fabricating equipment should be detected early in order to prevent a defective wafer from being produced and to prevent resources from being wasted. Detecting problems early helps to reduce a production cost and enhance a production yield
In order to detect problems with the fabricating equipment in the semiconductor fabricating process, a conventional method of analyzing past data by comparing the past data to a preset range value has been used.
However, various sets of identical equipment used in the semiconductor fabricating process are likely to continuously vary in their characteristics according to each process that is performed. Further, even though the identical sets of equipment may have identical settings, a variation and/or a deviation may arise between the identical sets of equipment.
In order to accurately determine whether the sets of equipment are functioning properly, a user has to occasionally correct and input the variation and/or the deviation. However, this is impractical. In particular, a method of compensating reference information for a periodic parameter and a method of evaluating the identical sets of equipment are needed. Accordingly, a conventional interlock system has been developed and used with the semiconductor fabricating process, wherein the interlock system instantly checks the reference information in real time and automatically updates the reference information according to a current situation of the semiconductor fabricating process.
The conventional interlock system is operated according to the reference information, which is previously set by a user. However, the interlock system cannot account for a variation in sensor information from various sensors that vary as the process is performed, or an internal variation in the sets of equipment. Thus, a problem arises in that it is difficult to account for an accidental difference between the sets of equipment. Therefore, the reference information for the respective sets of equipment needs to be individually set. This takes much time and expense.
Further, in the conventional interlock system, even though the sets of equipment are identical, it is difficult to account for the variation that arises as time goes by, so that a false alarm is likely to be raised. To reduce the likelihood of the false alarm, an allowable variation should be expanded. However, when the allowable variation is expanded, it is difficult to detect problems with some of the sensors.